Adduct of 5, 7, 9(11)-pregnatrien-20-one



pregnatrien-ZO-ones.

attached to carbon atom eleven.

tion products. gation is moreover emphasized by the acute short- Patented Apr. 21, 1953 UNITED STATES PATENT OFFICE ADDUCT OF 5,7,9 (11) -PREGNATRIEN-20-ONE Robert H. Levin, A. Vern McIntosh, Jr., and George B. Spero, Kalamazoo, Mich., assignors to The Upjohn Company, Kalamazoo, Mich, a

corporation of Michigan No Drawing. Application October 13, 1949, Serial No. 121,224

6 Claims.

The present invention relates to adducts of 3-substituted 5,7,9 (11) -pregnatrien-20-one with certain dienophilic acids, anhydrides, and esters,

and to a process for the production thereof.

The compounds of the present invention may be represented by the structural formula:

wherein B is selected from the group consisting of hydroxy and an acyloxy group derived from an organic carboxylic acid containing from one to ten carbon atoms, inclusive; and A is an adduct radical derived from a dienophile selectedfrom the group consisting of maleic acid, maleic anhydride, and maleic acid diesters containing from useful in the preparation of steroid compounds containing an oxygen atom at carbon atom eleven. Another object of the invention is the provision jof a process for adducts of production of the novel compounds, the 3-substituted-5 ,7,9(11)- Other objects of the invention will become apparent hereinafter.

The compounds of the present invention, as

previously stated, are useful in the preparation of steroid compounds having an oxygen atom Such compounds are of particular interest in the field of steroid research due to the biological activity of the cortical hormones and certain known derivatives thereof, which oxygenated steroids are known to have biological effects differing markedly from the unoxygenated steroids. It

-is, therefore, of importance to investigate the oxygenated derivatives of such adducts, particularly those oxygenated at carbon atom eleven,

as well as to investigate the biological activity of the adducts themselves and their transforma- The importance of such investiage of adrenal cortical hormones, and the ab 'sence of any present suggestion for alleviation 2 of the said shortage except through organic synthesis.

Novel compounds of the present invention which are of particular interest are those compounds of the above generic formula wherein 13 represents an ester of the 3-hydroxy group with a carboxylic acid containing up to and including ten carbon atoms. Among the acids which can be used are formic, acetic, propionic, butyric, valeric, hexanoic, heptanoic, octanoic, succinic, glutaric, cyclopentanoic, benzoic, toluic, naphthoic, and the like. Preferred acids are those containing from one to eight carbon atoms, inclusive, and especially such lower-aliphatic acids. The acids may also contain substituents, such as halo, alkyl, and methoxy, which are non-reactive under the reaction conditions employed. The adduct bridge A-) in such compounds may be represented by the graphic formula C-COOR it wherein R represents hydrogen or the organic residue of an alcohol. Such esters include the methyl, ethyl, propyl, isopropyl, butyl, isobutyl, lauryl, octyl, cyclohexyl, benzyl, and the like esters. The esterifying radical may also contain non-reactive substituents, such as halo,

methoxy, or hydroxy, if desired. While the esters of the maleic acid adduct are described herein with particular reference to the methyl. esters, the preferred embodiment of R is a lower-alkyl radical containing from one to eight carbon atoms, inclusive. Alternatively, the adduct may be depicted by the graphic formula:

8 H FAD-0 0 x/ Maa ll which is representative of the maleic anhydride adduct. i i

The compounds of the invention are usually colorless crystalline solids, which are insoluble in water, soluble in ether, halogenated hydrocarbons, acetone, ethyl acetate, and benzene. The acid anhydride adducts are readily converted to the free 3 hydroxy acid adduct by hydrolysis. These acid adducts in turn are readily converted into diester adducts by esterification with conventional reagents such as the diazoalkanes. [Wilds et al., J. Org. Chem. 13, 7.63, (1948.)1. Conversely, the diesters may be hydrolyzed to the dibasic acids which in turn may be converted into their corresponding anhydrides either :by' heat alone or preferably with a mild dehydrating agent such as acetic anhydride and the like.

The adducts of the present invention. are conveniently prepared by the selective oxidation of an enol ester of an adduct of 3-acyloxybisnor 5,7,9(11) cholatrien-22-al, represented by the formula:

wherein A and B have the values-previously given, B in this case. excluding the free hydroxy group.

Adducts of 3,22 diacyloxybisnor 5,7,9 ('11), 20(22)=cholatetraenes [22-eno1. esters of 3-acyloxybisnor-5,7,9(11) -cholatrien-,22-alsl are conveniently prepared by subjecting an adduct of a 3 acyloxybisnor 5,7',9('11) cholatrien 22 al, of the formula:

JEEP-CHO wherein A and B have the values previously'eiven, to the action or an acid anhydride. or an; aci halide in the presencev ofan alkaline salt of the acid. The starting adducts of 3-acyloxybisnor- 5,7,9(11) -cholatrien-22-als can be prepared from adducts of 3-esters of dehydroergosterol by selective oxidation as described and claimed in the copending application Serial 111,100of' Robert H. Levin, filed August 18, 1949, and as more fully described hereinafter.

The 3-esters of dehydroergosterol, from which the 3 acyloxybisnor 517,9(11) cholatrien- 22-a1 adducts are prepared, can be synthesized in several ways starting with ergosterol. For example, ergosterol can be transformed to dehydroergosterol with mercuric acetate according to known methods [Windaus et al., Ann. 465, 157 (1928)] and. the 3-hydroxy group of the dehydroergosterol acylated by known procedure. Alternatively the 3-hydroxy group of ergosterol can be acylated prior to the preparation of the dehydro derivative, a procedure which is particularly preferred in the preparation of the 3-acetoxy derivative. The adducts of the dehydroergosterol are then prepared by the addition of maleic anhydride or the like to dehydroergosterol or a 3-ester thereof according to known methods fHonigmann, Ann. 508, 89 (1934)]. The anhydrides can then be converted to their corresponding acids and esters if desired.

The ester group, when present in the 3-posi-tion of dehydroergosterol, is for the purpose of protecting the 3-hydroxy group in subsequent chemical reactions. For this purpose any convenient ester of an organic carboxylic acid, which is nonreactive under the conditions of the reaction, is suitable. The preferred acids are the fatty acids such as formic, acetic, propionic, butyric, Valerie, hexanoic, heptanoic, octanoic; dibasic acids such as malonic, succinic, phthalic; cycloaliphatic acids such as cyclopentanoic and cyclohexanoic; and aromatic acids such as benzoic, toluic, naphthoic, and the like. The acids may also contain substituents such as halogen, alkyl, the methoxy radical, and the like, and these substituents will be carried throughout the synthesis. If desired, the .acyl group can be changed to another acyl group by saponifying the ester to give a 3-hydroxy compound, which can then be re-esterified as previously described.

A preferred method for preparing some of the dehydroergosteryl adducts comprises the saponification of a 3-acyloxy-adduct of dehydroergosterol with dilute alkali followed by acidification. The 3-hydroxy dicarboxylic acid thus formed can be converted to the 3-hydroxy anhydride by heat, or it can be converted to any desired 3-acyloxy anhydride adduct by heating under reflux with the appropriate acid anhydride or chloride in pyridine solution. Dialkyl esters of the previously mentioned dicarboxylic. acid adducts can be prepared by subjectng the acid 'to the action of an ester-ification reagent such as a diazoalkane [Wilds et al., J. Org. Chem. 13, 763 (1948) l, e. g., diazomethane, diazoethane, dia-zobutane, and the like.

The selective oxidation of an adduct of dehydroergosterol, or a 3-ester thereof, to produce an adduct of 3-hydroxybisnor-5,7,9(1l)-ch0latrien-22-al, or a 3-ester thereof, is accomplished by dissolving the dehydroergosteryl adduct in a suitable solvent, cooling to about minus to plus 30. degrees centigrade, and passing ozone into the solution until about 1.0, to 1.25 moles of ozone per mole of adduct have been absorbed. The temperature of the solution should be maintained below plus 30 degrees centigrade, preferably between a temperature of minus 30 and minus 70 degrees centigrade, during the addition of ozone, although temperatures as low as minus 80 and as high as plus 30 degrees centigrade are operative. The lower temperatures of the preferred range are readily obtained by cooling the solution of the adduct with a bath of solid carbon dioxide in acetone or the like, although various other methods of cooling can be used. Many of the customary solvents used in ozonizations such as chloroform, acetic acid, carbon tetrachloride, ethylene chloride, methylene chloride, and the like, can be used.

The ozonides are then decomposed under reducing conditions, that is, in the absence of oxidizing agents, whether added or formed in the course of the reaction by products of decomposition. of the ozonide. This means that excess oxygen formed by decomposition of the ozonide must be prevented from forming, hydrogen peroxide by combining with any moisturev present, and that mol cular oxygen mu be prevented "from oxidizing the aldehyde thus formed. This can be conveniently accomplished by decomposing the ozonide in glacial acetic acid by the addition of finely-powdered zinc.

As is conventional with ozonizations when conducted in solvents, other than glacial acetic acid,

the solvent used for ozonization is replaced, after jcompletion of the ozonization, by adding glacial acetic acid and removing thelower-boiling sol vent by fractional distillation. Alternatively, the

solvent can be removed by careful warming under reduced pressure prior to the addition of glacial I acetic acid, if desired.

After decomposition of the ozonide and removal of the zinc, the aldehyde can be recovered by diluting the acetic acid with water, or in other consponding 3-hydroxy or acyloxy aldehyde maleic acid, maleic acid anhydride, or maleic acid ester adduct with a large excess of an organic carboxylic acid anhydride in the presence of a small amount of the alkali metal salt or" the acid corresponding to the anhydride employed or an acid catalyst such as para-toluene sulfonic or sulfuric acid. The preferred anhydride is acetic anhydride, but other anhydrides, such as pro- 'pionic, butyric, Valerie, hexanoic, and octanoic 'anhydrides, as well as benzoic acid anhydride,

ortho-toluic acid anhydride, naphthoic acid anhydride, and the like, are also operative. The acid anhydrides can also be substituted by non-reactive groups, such as halo, alkyl, and methoxy, as

in the case of chloroacetic, ortho-toluic, or methoxybenzoic acid anhydrides. The reaction can -be conveniently followed by observing the color Y changes in the reaction mixture, optimum yields being obtained by discontinuing the application of heat when the color of the solution changes from yellow to brown. is heated at about 140 degrees centigrade for from about four to six hours, but temperatures Ordinarily the reaction as low as 100 and as high as 180 degrees centigrade are also operative. The reaction is usually conducted at the boiling point of the anhydride, but in the case of the higher-boiling anhydrides,

such as benzoic anhydride, a suitable temperature control, such as 100-150 degrees centigrade,

'must be used, since the adduct otherwise tends to decompose in the higher temperature range.

If a 3-hydroxy aldehyde adduct is thus reacted with an anhydride, the hydroxyl group will be acylated, and, similarly, if a maleic acid adduct is used instead of a diester or an anhydride, the

anhydride will be formed. The enol ester can be isolated by removing the excess anhydride un- 'der reduced pressure, and separating the enol ester from alkali metal salts, which procedure yields a product sufficiently pure for most purposes, but which can be further purified by recrystallization from acetone-Water, acetone-pentane, or like pairs of solvents, if desired.

The ozonization of the thus-prepared enol -acylate according to the method of the present invention involves dissolving the enol ester in a suitable solvent, cooling to about minus eighty degrees Centigrade to plus thirty degrees centi- -grade, and passing ozone, ozonized air, or ozo- ,nized oxygen into the solution until about 1.0 to about,1.25 moles, preferably 1.0 to 1.1 moles,

,6 of ozone per mole of adduct have been absorbed. The addition of ozone to the 20:22 double bond is so rapid that only a small amount of ozone escapes from the reaction mixture, and the amount of ozone ordinarily required therefore closely approximates the theoretical amount. Loss to the solvent, if any loss occurs, must be taken into consideration in calculating the amount of ozone to be introduced. The temperature of the solution should be maintained below plus thirty degrees centigrade, preferably between a temperature of minus thirty and minus seventy degrees centigrade, during the addition of ozone, although temperatures as low as minus eighty and as high as plus thirty degrees centigrade are operative. The lower temperatures of the range are readily obtained by cooling the solution of the adduct with a bath of solid carbon dioxide in acetone or the like, although various other methods of cooling may be employed. Many of the customary solvents used in ozonizations, such as chloroform, methylene chloride, ethylene chloride, carbon tetrachloride, acetic acid, and the like, can be used for the ozonization reaction.

The 20 :22 ozonides thus produced are then decomposed under conditions normally employed for decomposition of such compounds. This can conveniently be accomplished by decomposing the ozonide with hydrogen peroxide, by hydrolysis, with zinc in glacial acetic acid, or by a catalytic amount of colloidal metal such as: silver, platinum, or palladium in a solvent, such as glacial acetic acid, alcohol, or ethyl acetate, in

i which latter case a hydrogen atmosphere is also employed. The use of reductive conditions is well established in the art [Hill and Kelly, "Organic Chemistry, page 53, The Blackiston Company, Philadelphia (1934); Church et al., J. Am. Chem. Soc. 56, 176-184 (1934); Gilman Organic Chemistry, Second Edition, page 636, John Wiley and Sons, New York (1943) Long, Chem. Reviews 27, 452-454 (1940) l.

As is conventional with decomposition of ozonides with zinc, when the ozonizations are conducted in solvents other than glacial acetic acid,

the solvent used for the ozonization is replaced, after completion of the ozonization, by adding glacial acetic acid and removing the lower-boiling solvent by fractional distillation, or the solvent can be removed by careful warming under reduced pressure prior to the addition of acetic acid, if

desired. After decomposition of the 20:22 ozonide and removal of the metal, the ketone can be recovered by diluting the acetic acid with Water, or by other conventional procedure :for the -recovery of ketones, such as by formation of a carbonyl derivative, e. g., the 2,4-dinitrophenylhydrazone. Recrystallization from acetone or the like results in a more highly purified ketone PREPARATION 1.DIMETHYL MALEATE Annual or DEHYDROERGOSTERYL BENZOATE To a solution of 21, grams of dimethyl maleate adduct of dehydroergosterol in 69 milliliters of warm pyridine was added 9.5 milliliters of benzoyl chloride. After standing at room temperature for fifteen minutes, the mixture was poured into 1400 milliliters of ice-water and the solid .removed by filtration, dried, and recrystallized from acetone. There was thus obtained 26.4

grams of dimethyl maleatev adduct of dehydroergosteryl benzoate, melting at 203 to 205.5 degrees centigrade.

PREPARATION 2.DIMETHYL MALEATE AnDUcT 01 DEHYDROERGOSTERYL ACETATE In a manner essentially that described in Preparation 1,.the dimethyl maleate adduct of dehydroergosteryl acetate, melting at 177 to 179 degrees centigrade, was prepared from the dimethyl maleate adduct of dehydroergosterol and acetyl' chloride.

PREPARATION 3.-DIMETIIYI. MALEATE Ammcr or DEHYDROERGOSTEBYL FORMATE A solution of six' grams of dimethyl maleate adduct of dehydroergosterol in fifty milliliters of 8'7 percent formic acid was heated under reflux for one hour, cooled, and the dimeth yl maleate adduct of dehydroergosteryl formate filtered therefrom. Upon crystallization from acetone, the purified material melted at 177 .5 to 178.5 degrees centigrade.

PREPARATION 4c.MALEIC ACID ADDUoT or DEI-IYDROERGOSTEROL Twelve grams of the maleic anhydride adduct of dehydroergosteryl acetate was dispersed in 300 milliliters of methyl alcohol, whereafter a solution of 2.6 grams of potassium hydroxide in 300 milliliters of water was added to the suspension and the reaction mixture heated under reflux for 135 minutes, 200 milliliters of water being added portionwise during the reaction period. The hot solution was filtered to remove any undissolved solid, cooled, and acidified. After washing the precipitate with water and drying, there was obtained 9.2 grams of the maleic acid adduct of dehydroergosterol, melting at 190-192 degrees centigrade.

PEErAImTIoN 5.MALEICI ANHYDRIDE AnoUcT F 3- HEPTANOYLOXYDEHYDROERGOSTEROL The maleic acid adduct of dehydroergosterol from Preparation 4' was dissolved in a mixture of seven milliliters of warm pyridine and fourteen milliliters of heptylic anhydride, and the mixture heated under reflux for one hour. About eighty percent of the reaction solvent was removed under reduced pressure, and the residue then dissolved in methyl alcohol. The methyl alcohol solution was concentrated and cooled to yield 4.8 grams of the maleic anhydride adduct of 3- heptanoyloxydehydroergosterol, melting at 186- 1915 degrees centigrade.

PREPARATION 6.-MALEI0 ANHYDRIDE ADnUcT or 3- BETA-AcEToxYBIsNoR-5,7,9,11-cH0LATaIEN-22-AL A solution of 5.35 grams of the maleic anhydride adduct of 3beta-acetoxydehydroergosterol in 107 milliliters of methylene chloride was cooled to about minus seventy degrees centigrade and ozonized until 505 milligrams of ozone had been absorbed. The temperature of the solution was then gradually raised to about plus ten to fifteen degrees centigrade, whereupon seventy milliliters of glacial acetic acid was added and the methylene chloride removed under reduced pressure. Seven grams of zinc dust was then added to the cold solution at a uniform rate over a period of ten minutes, while keeping the reaction temperature below plus twenty degrees centigrade. After being stirred for fifteen minutes, the mixture was filtered and the filtrate poured into water. There was thus obtained 4.31 grams of maleic anhydride adduct of 3-betaacetoxybisnor-5,7,9 I1 -cholatrien 22-.al, a fine white powder which' melted at' 187-197v degrees centigrade.

To a solution of 0.30 gram of the maleic anhydride adduct of 3-beta-acetoxybisnor-5;Z,9- (l1) cholatrien-22-al, in thirty milliliters. of ethanol, was added twenty milliliters of alcohol containing one percent ZA-dinitrophenylhydrazine and three percent concentrated hydrochloric acid. The mixture was allowed to stand for one hour at room temperature and then placed in a refrigerator to complete precipitation of the yellow crystals. Theprecipitate was then collected and recrystallized from a mixture of chloroform and alcohol, to give thev 2,4-dinitrophenylhydrazone of themaleic anhydride adduct of 3-b.eta-acetoxybisnor-5,7,9 (-11) -cholatrien22- al, melting at 269-271 degrees centigrade.

PREPARATION 7.-MALEI0 ANHYDRIDE ADDUCT'OF 3- BETA-ACETOXYBISN 0B-5,7,9 (11) -CHOLATRIEN-22-AL Atwo-liter, round-bottom flask was charged with fifty'grams (0.93 mole) of dehydroergosteryl acetate maleicanhydride adduct and. one liter-of methylene chloride. The solution was cooled to Dry-Ice. temperature with a trichloroethylene bath and ozonized oxygen passed through at a rate of 1200 milliliters of oxygen per minute (at this rate the ozonizer was producing about 36 milligrams of ozone per minute). The flow of ozonized oxygen was maintained for 128 minutes, a total of 4608 milligrams percent) of ozone being passed into the solution. The reaction mixture was transferred to a two-liter, roundbottom flash fitted with a capillary and a condenser for downward distillation, 300 milliliters of acetic acid added, and the methylene chloride distilled over in vacuo at forty degrees centigrade or below. The flask was then placed in a water bath and fitted with a stirrer. An additional 200 milliliters of acetic acid was added and the ozonide decomposed by the addition of fifty grams of zinc dust. The zinc dust was added in portions over a period of twenty to thirty minutes while the solution was stirred and the temperature maintained at seventeen to twenty degrees centigrade. After addition, the mixture was stirred for another twenty minutes and then filtered. The precipitated zinc dust was washed by filtering 100 milliliters of acetic acid therethrough, and the filtrate gradually diluted with water (1100 to 1200 milliliters) until the prodnot had been drowned out. The product was then cooled in the refrigerator overnight and filtered. The yield of crystalline product was 42 grams, assaying 89-95 percent of the desired aldehyde.

PREPARATION 8 In a manner essentially that described in Preparation 6, the following compounds were prepared:

1. Maleic anhydride adduct of 3-beta-formoxybisnor-5,7,9 (11) -cholatrien-22-al, melting at 95- degrees centigrade. 2,4-dinitrophenylhydrazone, melting at -168 degrees centigrade.

2. Maleic anhydride adduct of 3-beta-heptanoyloxybisnor 5,7,9(11) cholatrien 22 a1, melting at 197.5-199 degrees centigrade. 2,4- dinitrophenylhydrazone, melting at 253-257 degrees centigrade.

3. Dimethyl maleate adduct of S-beta-benzoyloxybisnor-5,7,9 11) -cholatrien-22-al, melting at 183-187 degrees centigrade. 2,4- dinitrophenylhydrazone, melting at 224-249 degrees centigrade.

4. Dimethyl maleate adduct of 3-beta-acetoxy- PREPARATION 9.DIMETHYL MALEATE ADDUCT or 3- HYDROKYBISNOR-5,7 ,9 11 -CHOLATRIEN-2-2-AL A solution of 2.69 grams (.005 mole) of the dimethyl ester of the maleic acid adduct of dehydroergosterol, in eighty milliliters of methylene chloride, cooled by a Dry-Ice and trichlorrethylene bath, was treated with ozonized oxygen until 247.36 milligrams (.0051 mole) of ozone was absorbed. The solution was then allowed to warm to room temperature, whereafter thirty mil liliters of acetic acid was added and the methylene chloride removed in vacuo. While cooling in a water-bath at fifteen degrees centigrade,

four grams of zinc dust was added in portions, with stirring, the temperature being maintained between fifteen and twenty degrees centigrade.

Stirring was continued for another fifteen minutes, whereafter the zinc was separated by filtration. The filtrate was diluted with water to cloudiness, extracted with ether, the ether extract washed with sodium bicarbonate and then with water to neutrality, the solution then dried over sodium sulfate and evaporated to dryness in vacuo. The residue was crystallized from acetic acid and water, giving 1.92 grams (81.5

percent of the theoretical), melting point 91-97 degrees centigrade, which yielded a dinitrophenylhydrazone derivative in 72.5 percent yield, melting point 212-238 degrees centigrade. The aldehyde was recrystallized and found to have a purified melting point of 163-170 degrees centigrade, while the dinitrophenylhydrazone derivative was recrystallized until a melting point of 250-254 degrees centigrade was attained.

PREPARATION 10.-THE MALEIC ANHYDRIDE ADDUGT or 3-BETA-ACETOXY-22-ACETOXYBISNOR-5,7,9(11) ,20-

(22) -CHOLATETRAENE A mixture of twenty grams of the maleic anhydride adduct of 3-beta-acetoxybisnor-5,7,- 9(11)-cholatrien-22-al, six grams of anhydrous sodium acetate, and 600 milliliters of acetic anhydride, was heated under reflux for six hours, whereafter volatile components were removed under reduced pressure. The resulting solid was digested with five fifty-milliliter portions of boiling acetone for five minutes each, and the extracts combined and diluted with 130 milliliters of water. There was thus obtained sixteen grams of the maleic anhydride adduct of 3-be taacetoxy-22-aoetoxybisnor 5,7,9(l1), 20(22) cholatetraene, which melted at 186 to. 193 degrees centigrade. Recrystallization of the crude product from a mixture of acetone and pentane raised,

the melting point to 2,4-dinitrophenyl- PREPARATION 11 J In a manner essentially that described in Preparation 10,, the following compounds were prepared:

1. The dimethyl maleate adduct of 3-beta-benzoyloxy 22 acetoxybisnor 5,7,9(11),20(22)-' cholatetraene, which melted grees centigrade.

2. The dimethyl maleate adduct of 3-betaacetoxy-22-acet0Xybisnor-5,7,9 (11) ,20 (22) -cholatetraene, which melted at 181 to 183 degrees centigrade.

In the same manner as given above, 221-acyloxy, e. g., formoxy, acetoxy, propionoxy, butyroxy, valeroxy, hexanoyloxy, heptanoyloxy, octanoyloxy, benzoyloxy, naphthoyloxy, and the like 3- acyloxybisnor5,7,9 (11) ,20 (22) -cholatetraene adducts, are obtained from the compounds of Prep arations 6, 7, and 8. Such representative compounds include 3 formoxy 22 acetoxybisnor- 5,7,9 (11) ,20 (22) -cholatetraene, 3-propionoxy-22 acetoxybisnor 5,7,9(11),20(22) cholatetraene,

at 210 to 211 (18- 3,22 dipropionoxybisnor-5,7,9(11) ,20 (22) -cholatetraene, 3,22 dibenzoyloxybisnor 5,7,9(1l),-

20(22)- cholatetraene, and 3 heptanoyloxy 22- octanoyloxybisnor 5,7,9(11),20(22) cholatetraene adducts with maleic anhydride or maleic acid esters such as the dimethyl maleate, diethyl maleate, dipropyl maleate, diisopropyl maleate, dibutyl maleate, dioctyl maleate, dibenzyl maleate, and the like.

Example 1.-Maleic anhydride adduct of 3-betadeeming-5,7,9 (11) -pregnatrien-20-one milliliters of glacial acetic acid was then added,

and the methylene chloride removed under reduced pressure. An additional thirty milliliters of glacial acetic acid was then added and the ozonide decomposed by adding seven grams of powderedzinc at a substantially uniform rate while maintaining the reaction temperature be-' tween seventeen and twenty degrees centigrade. The mixture was stirred for an additional twenty minutes, filtered, and the zinc washedwith milliliters of glacial acetic acid. The organic extracts were combined and diluted with seventy milliliters of water. When crystallization commenced, the rate of precipitation was increased by addition of two;volumes of water. There was" thus obtained 4.0 grams of the maleic anhydride adduct of 3-beta-acetoxy-5,7,9 (11) -pregnatrien- 20-one, which melted at 240 to 264.5 degrees centigrade. Several recrystallizations of the crude material from acetone raised the melting point to 263.5 to 264.5 degrees centigrade.

Example 2.-Male2'c acid adduct of 3-beta-hydr0my-5,7,9(11) -pregnatrzen20-one A solution of one gram of sodium hydroxide 111 five milliliters of water was added with stirring to a suspension of one gram of the maleic anhydride adduct of 3-beta-acetoxy-5,7,9(11) -pregnatr1en-20-one at room temperature, a turbid solution forming almost immediately. After standing for thirty minutes, the addition of thirty mil-:

liliters of water resulted in a clear solution. This was allowed to stand for six hours, then made ac d by addition, of three normal hydrochloric to d y s 111* acid and diluted with water to 100 milliliters. The weakly turbid mixture was placed in the re irigerator, whereafter 0.6 1 gram of the maleic acid adduct of 3-beta-hydroXy-5,7,9(11) -pregnatrien -20-one, melting at 211-215 degrees centigrade, precipitated therefrom. After several crystal-lizations from an acetoneewater mixture, the adduct melted at 171-184 degrees eentigrade.

Emmzzle. a-mme y ma ewte. 0.1 3-betaydreary-51,901) -prcgnatrien-20-one A suspension of 0.400 gram of the maleic acid adduct of 3-.beta-hydroxy-5,7,9( 11) -preg natrien- 20-one, in fifty milliliters of dry ether, was cooled in an ice-salt bath while a slight excess of diazomethane in methylene chloride was added over a 25-minute period with stirring. Ten minutes after addition was. complete, the solution was placed on a steam bath and concentrated rapidly The residue was. crystallized from an acetone-water mixture to give 0.34 gram of the dimethyl maleate of 3 beta hydroxy- 5,7,!)(11)-pregnatrien-20.-one, melting at 193-195 degrees. centigrade. After chromatography and recrystallization, the compound melted at 192-197 degrees Centigrade.

In the same manner as given above, other dialkyl maleates, e. g., the diethyl, dipropyl, diisopropyl, dibutyl, and dioctyl maleates of B-hydroxy-5,7,9(11) -pregnatrien-20-one are prepared from 3-hydroxy-5,7,9 (11) pregnatrien-ZO-one maleic acid adduct and the appropriate diazoalkane, or by other equivalent esterification procedure.

Example 4.--D,z",'ne,th1/Z: maleate of 3-.beta-acetory- 5.,7,9(11) -preg.natrien-20-one A solution of 0.15 gram of the dimethyl maleate adduct of 3.-beta-hydroxy-5,7,9(11) -pregnatrien- 20,-one, in 2.5 milliliters of acetic anhydride and 2.5 milliliters of pyridine, was heated on the steam bath for ninety minutes, cooled toroom temperature, and poured into ice-water. The resulting precipitate was collected by filtration and found to melt at 205-209 degrees centigrade. Recrystallization from methanol gave the dimethyl maleate of 3-beta-acetoxy-5,7,9(11)- pregnatrien-ZO-one, melting at 207-211 degrees centigrade.

ANALYSIS Calcmated for CzeHssOs; c, 69.86;, 7.68 Found: 69.81; 7.86 69.70; 7.62

By the same manner of, esterification, the following C-3 esters were prepared: (1) dimethyl maleate' adduct of 3-beta-formoxy-5,7,9(11)- pregnatrien-ZO-one, melting point 223-230 degrees centigrade, and (2) the dimethyl maleate adduct of 3-beta-benzoyloxy-5,7,9(11) -pregnatrien-20-one, melting point 250-254 degrees cenrade.

Example 5.-Maleic anhydride adduct of 3-betaheptanoyZxy-5,7, 9 (11 -pregnarrien-20-one The maleic anhydride adduct of B-beta-heptanoyloxy-5,7,9 (1 1) -pregnatrien-20-one, melting point 170-171 degrees centigrade, was prepared by refluxing themaleic acid adduct of 3-betahydroxy=5.,7,9(11) epregnatrien-20-one with heptxliaanhydride and pyridine for a period of twen- W ours, and Working up. h reaction p QdllQt in the usual manner.

Example 6'.-Malcic anhydrzde adduct 0 3-beta-j hydrory-5,7,9-(1-1) -pregna,trien.-20-one;

prepared by refluxing the maleic. acid adduct of.

3 beta, hydroxy 5,7,9(11) pregnatrien-20-one with Dowtherrn for eight hours, maleic anhydride adduct is also obtained by heating the 2,-hydroxy maleic acid adduct, to just. above its melting point, which procedure causes water to be evolved, with the closing of the. an hydride ring. r

In the same manner as, given above, still other 5,7,9(11)-pregnatrien-20-one adducts are pre pared from the corresponding 3,22-diacyloxybisnor-5,7,9(11),20(22)-cholatetraene maleic acid anhydride, and maleic, acid, diester adducts. Such compounds Within the scope oi the invention, include the 3-formoxy-5,7, 9 (ll) -p regnatrien-ZO-one maleic acid, maleic acid anhydride, dimethyl maleate, diethyl maleate,, dibutyl' maleate, dioctyl maleate, diisopropyl maleate, dibenzyl maleate, and like adducts; the. corresponding 3-propionoxy, butyroxy, valeroxy, hexanoyloxy, heptanoyloxy, octanqyloxy, naphthoyloxy, benzoyloxy, and similar ZO-ketone adducts, including, for example, 3-propionoxya. 5,7,9( 11)-preg natrien-20-one dipropyl maleate, 3-benzoyloxy-5,7,9(11)- pregnatrien -.v 2.0-one dibenzyl maleate, 3-heptanoyloXy-5,f7, -(11).-:preg! natrien-ZO-one dimethyl maleate,. 3.-val'eroyloxy-, 5,7,9(l1) -pregnatrien-20-one maleic acid an,- hydride adducts, and the like.

It is to be understood that the invention is not to be limited to the exact details of operation or exact compounds shown and described, as obvious. modifications and equivalents will be apparent to, one skilled in the art, and the invention is therefore to be limited only by the scope of thewape pended claims.

We claim:

1. A 5,7,9.(1l)-pregnatrien-20-one. adduct 01 the formula:

Q=Q on: I

wherein B is selected from the roup consistin of hydroxy and an acyloxygroup ACQAO bein the radical of an. unsubstituted or anic monocarboxylic acid containing from one to. tens car-. bon atoms, inclusive, and wherein A is. the. adductv radical of a dienophile selected from. the group consisting of maleic acid, maleic. acid anhydride, and maleic acid diesters wherein the esterifying group is solely of a. hydrocarbon nature and contains from one to eight carbon atoms, inclusive.

' 2. Maleic anhydride adduot. of: 3.--acetm v- 5,7,9(11)-pregnatrien-20-one. a

The 3-hydroxy.-.

13 3. Maleic acid adduct of 3-hydroxy-5,7,9(11)- pregnatrien-20-one.

4. Dimethyl maleate adduct of 3-hydroxy- 5,7,9 (11) -pregnatrien-20-one. Number 5. Dimethyl maleate *adduct of 3-acetoxy- 5 2,156,275 5,7,9 (11) -pregnatrien-20-one. 2349311 6. Maleic anhydride adduct of 3-hydr0xy- 2,296,284 5,7,9 (11) -pregna.trien-20-one. 2313732 ROBERT H. LEVIN. 23871830 A. VERN McIN'IOSI-I, JR. 1o GEORGE B. SPERO.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Butenandt May 2, 1939 Oppenauer et a1. July 22, 1941 Julian Sept. 22, 1942 Butenandt Mar. 16, 1943 Butz Oct. 30, 1945 

1. A 5,7,9(11)-PREGNATRIEN-20-ONE ADDUCT OF THE FORMULA: 